ARC and objc_getClassList do not get along

gistfile1.m

// clang -framework Foundation -fobjc-arc test.m

#import <objc/runtime.h>
#import <stdio.h>
#import <stdlib.h>


int main(int argc, char **argv)
{
    @autoreleasepool
    {
        int count = objc_getClassList(NULL, 0);
        Class buffer[count];
        objc_getClassList(buffer, count);
        
        for(int i = 0; i < count; i++)
        {
            Class c = buffer[i];
            
            // see if c is in the NSObject hierarchy
            BOOL isNSObj = NO;
            
            // this will crash here when trying to retain a class which shouldn't be messaged
            for(Class candidate = c; candidate != Nil; candidate = class_getSuperclass(candidate))
            {
                if(candidate == objc_getClass("NSObject"))
                    isNSObj = YES;
            }
            if(!isNSObj)
                fprintf(stderr, "%s is not in the NSObject hierarchy\n", class_getName(c));
        }
    }
    
    return 0;
}